| 摘要 |
The present invention provides a process for preparing a supported chromium-based catalyst for the production of polyethylene comprising the steps of a) providing a silica-based support having a specific surface area of at least 250 m2/g and of less than 400 m2/g and comprising a chromium compound deposited thereon, the ratio of the specific surface area of the support to chromium content being at least 50000 m2/g Cr; b) dehydrating the product of step a); and c) titanating the product of step b) in an atmosphere of dry and inert gas containing at least one vaporised titanium compound of the general formula selected from RnTi(OR')m and (RO)nTi(OR')m, wherein R and R' are the same or different hydrocarbyl groups containing from 1 to 12 carbon atoms, and wherein n is 0 to 3, m is 1 to 4 and m+n equals 4, to form a titanated chromium-based catalyst having a ratio of specific surface area of the support to titanium content of the titanated catalyst ranging from 5000 to 20000 m2/g Ti. ® KIPO & WIPO 2009 |
